How 3PLs Make Money: The Truth About Shipping Margins, Fulfillment Fees, and What Brands Should Know

How 3PLs Make Money: The Truth About Shipping Margins, Fulfillment Fees, and What Brands Should Know

The Truth About How 3PLs Make Money 

When brands evaluate third-party logistics providers (3PLs), the conversation almost always starts with fulfillment pricing.

Is pick and pack $1.50 or $2.25 per order?

Is there a $0.40 insert fee?

Are returns $3 or $4?

Those questions are reasonable and completely normal. But they do not always address the biggest cost driver in your fulfillment operation.

For most 3PLs, shipping margin plays a larger role in their economics than fulfillment labor. That is not a bad thing. It is standard industry practice. The key for brands is understanding how it works and making sure it is evaluated alongside fulfillment fees.

Where 3PL Revenue Really Comes From

Most 3PLs make money in three primary ways:

• Fulfillment services such as pick, pack, storage, and returns

• Value-added services like inserts, kitting, labeling, and prep

• Shipping margin, which is common, expected, and often the largest lever

Fulfillment and value-added fees are clearly listed on rate cards. Shipping margin is typically embedded within carrier charges, which can make it harder to evaluate at a glance.

That does not make it hidden or unfair. It simply means brands need to ask the right questions.

Why Shipping Margins Are Normal and Expected

3PLs ship thousands or millions of packages per year across many brands. That scale allows them to negotiate carrier rates that individual merchants usually cannot access on their own.

However, not all 3PLs are created equal.

Each 3PL has its own:

• Negotiated carrier agreements

• Volume commitments and rate cards

• Dimensional weight (DIM) factors

• Fuel and surcharge treatment

• Internal shipping markup strategy

This means two 3PLs shipping the exact same order can arrive at very different shipping costs, even before fulfillment fees are considered.

Those negotiated discounts are rarely passed through at cost. Instead, 3PLs apply a markup to shipping to cover carrier negotiations, billing complexity, fuel and surcharge volatility, technology, and operational overhead.

This approach is widely used across the industry. The goal is not to eliminate shipping margin. The goal is to understand it, compare it, and make sure it scales fairly as your business grows.

Why Shipping Quotes Matter More Than Pick and Pack

Brands often focus heavily on fulfillment fees.

A $1.50 versus $2.25 pick and pack rate

A $0.40 insert fee

A $3 versus $4 return processing fee

Those costs feel tangible and easy to negotiate.

Shipping, however, is usually the largest line item on the invoice, and the one most affected by carrier contracts, markups, and dimensional rules.

A Simple Example Using Real Numbers

Assume you ship 10,000 orders per month and the 3PL’s underlying carrier cost is $9.00 per package.

3PL A applies a 10 percent shipping markup and charges $9.90 per shipment.

3PL B applies a 20 percent shipping markup and charges $10.80 per shipment.

That is a $0.90 difference per order driven entirely by shipping margin.

Over 10,000 monthly orders, that difference equals $9,000 per month or $108,000 per year.

Now compare that to fulfillment fees.

A $0.75 difference in pick and pack pricing saves $7,500 per month.

A $0.40 insert fee applied to every order saves $4,000 per month.

A $1 return processing difference on 10 percent of orders saves $1,000 per month.

In this scenario, shipping margin alone has a larger financial impact than all three fulfillment line items combined.

Where Shipping Margins Can Increase Further

Shipping markups are rarely flat across all services.

Higher margins are commonly applied to heavier or oversized packages, dimensional weight shipments, expedited services such as two-day or next-day air, and international or cross-border orders.

Dimensional weight rules matter here as well. Some 3PLs operate under different DIM factors than others, which can materially change billable weight and cost for the same package.

This is standard practice and not inherently negative, but it reinforces why brands should review real shipping examples rather than relying on averages.

Smart Questions Brands Should Ask

Brands do not need to challenge their 3PL. They simply need to ask informed questions.

Can you provide sample shipping quotes by zone and weight?

What DIM factor do you use for each carrier and service level?

Do shipping rates improve at higher monthly volume tiers?

Are there additional carrier discounts as we scale?

Are expedited or oversized shipments marked up differently?

How are peak season surcharges handled?

If our order profile changes, do shipping economics change too?

Many 3PLs offer better rates at defined volume tiers, but those improvements are not always automatic unless they are discussed up front.

Practical Tips for Brands Evaluating 3PL Shipping

Ask for real, recent shipping samples rather than averages.

Compare shipping costs using your actual SKU weights and dimensions.

Confirm whether rate reductions apply as volume grows.

Understand which fees are pass-through versus margin-based.

Revisit shipping economics annually as your business scales.

A 3PL with a $2.25 pick and pack rate but fair, transparent shipping economics can easily be more cost-effective than one advertising $1.50 pick and pack with higher shipping margins.

The Bottom Line for Brands

Shipping margin is normal, common, and expected in 3PL relationships.

What matters is not eliminating it. What matters is understanding how it works, how it differs from provider to provider, and making sure it aligns with your growth. Brands that evaluate shipping quotes alongside fulfillment pricing make better decisions, avoid surprises, and build stronger long-term partnerships.

In logistics, the smartest brands do not just compare rate cards. They compare real-world outcomes.